Apparatus for handling molten metal



Sept. 12, 1967 c, L 3,341,187

APPARATUS FOR HANDLING MOLTEN METAL Filed March 22, 1965 4 Sheets-Sheetl a 9 LL. 3; z 3? X IS I Q H H I'QJ i $1,

2 r 29 \l 52 n 1- 2 r/bl 2 E INVENTOR 5E CLIFFORD M. LUNA 53 ATTORNEYSSept. 12, 1967 c, LUNA 3,341,187

APPARATUS FOR HANDLING MOLTEN METAL Filed March 22, 1965 4 Sheets-Sheet2 sl- 34 5| INVENTOR CLIFFORD M.LUNA FIG. 2

BY M a-Md ATTORNEYS Sept. 12, 1967 c. M. LUNA APPARATUS FOR HANDLINGMOLTEN METAL 4 Sheets-Sheet Filed March 22, 1965 INVENTOR CLIFFORD M.LUNA BY 7 M i ATTORNEYS Sept. 12, 1967 c. M. LUNA 3,341,187

- APPARATUS FOR HANDLING MOLTEN METAL Filed March 22, 1965 v 4Sheets-Sheet 4 INVENTOR CLIFFORD M. LUNA @ztmw, BY F f ATTORNEYS UnitedStates Patent Oil ice H 3,341,187 APPARA TUS FOR HANDLING MOLTEN METALClifford M. Luna, Jefferson County, Ala., assiguor to United States Pipeand Foundry Company, Birmingham, Ala., a corporation of New Jersey FiledMar. 22, 1965, Ser. No. 441,792 4 Claims. (Cl. 266-38) ABSTRACT OF THEDISCLOSURE Apparatus for handling hot met-a1 from a melting furnacecomprising three ladles tiltably mounted on a turntable by means ofwhich they may be successively and simultaneously moved between areceiving station where metal is received, a treating station and apouring station.

This invention relates to hot metal treating facilities for foundries.More particularly it relates to an apparatus for melting, treating andhandling large amounts of metal over extended periods of time.

In many plants such as cast iron pipe foundries, it is necessary tooperate cupolas for long periods of time at high melting rates and thereis a continuous demand for molten metal. Due to many factors, it isimpossible to obtain a stream of metal from the cupola which has thedesired composition at all times. Therefore, every effort is made tooperate the cupola so that the average composition is equal to thedesired composition. A forehearth of suitable size to even out thefluctuations in the spout composition is provided and molten metal istaken from the forehearth at the same rate as it is added from thecupola.

Even with the use of a forehearth, it is often either impossible oruneconomical to operate the cupola so as to obtain the desiredcomposition. For example, in melting metal for ductile iron productionin an acid cupola the sulfur content is too high and it is necessary totreat the metal to reduce the sulfur. In addition, when high steelcharges or low blast temperatures are used and it is desired to obtainrelatively high spout temperatures and to maintain high melting rates,the carbon and silicon contents of the melt are generally low. As aresult, it is necessary to treat the metal to correct the deficiencies.

Attempts to continuously treat at the cupola spout or in the forehearthhave not been completely satisfactory for several reasons. For example,when continuously desulfurizing-it is difficult to obtain uniform mixingof or contact between the metal and treating agent, it is necessary tocontinuously remove slag which will of necessity contain fresh unreactedmaterial, and it is difficult to obtain clean metal from the forehearth.Also, it is often desirable to operate the cupola with raw materials andunder conditions which will result in spout compositions which do notaverage out to a desired composition in the forehearth. In thissituation it is not possible to continuously treat or make additionswith certainty that the desired composition will result since theforehearth composition is constantly changing in an unknown manner.

Batch treatment in ladles is not satisfactory because the ladles aregenerally small in size so that it is impractical to obtain an analysisof each ladle. Also, the temperature drop is excessive, and in generalthe operation cannot economically and satisfactorily provide largequantities of treated metal of the desired composition and temperature.

Accordingly, this invention has for its object the provision of anapparatus which will permit the continuous operation of a meltingfurnace, the collection of a suitable amount of metal to give a maximumaveraging of the metal composition coming from the furnace, the analyza-3,341,187 Patented Sept. 12, 1967 tion of the collected metal and thetreatment of the analyzed metal in an economical operation whichprovides a substantially continuous supply of metal of desired analysisand temperature.

Other objects and advantages of the invention will be readily apparentfrom the following written description of the invention set forth in thespecification and the embodiments illustrated in the drawings in which:

FIGURE 1 is a plan view layout of the new apparatus in which theequipment components are illustrated more or less diagrammatically.

FIGURE 2 is a front elevation view of a ladle car which comprises asegment of the turntable illustrated in FIGURE 1.

FIGURE 3 is a plan view of the ladle car shown in FIGURE 2.

FIGURE 4 is a sectional view of a presently preferred embodiment takenalong line IVIV of FIGURE 1.

FIGURE 5 is a sectional view of a presently preferred embodiment takenalong line VV of FIGURE 1.

FIGURE 6 illustrates an alternate method of mounting the ladle coverabove the ladle at the pouring station so that it may be tilted with theladle.

Turning to FIGURE 1, the apparatus is seen to comprise a turntable Imounted adjacent the tapping spouts 2 of a bank of cupolas 3. Mounted onthe turntable 1 are three identical large ladles 4, 5 and 6 which areevenly spaced about the turntable. When ladle 4 is adjacent the meltingstation, ladle 5 is adjacent a treating station and ladle 6 is adjacenta pouring station. Ladle 4 at the melting station receives molten metalfrom either or both of cupolas 3 through ducks nest basin 7 which isprovided to interrupt the flow of metal from the cupolas while theturntable is rotated to move full ladle 4 to the treating station andempty ladle 6 from the pouring station to the melting station.

In the open center of the turntable, in fixed position opposite thetreating station, ladle tilting mechanism 8 is provided to permittilting of ladle 5 to assist in slagging operations. Also in the opencenter of the turntable there is provided a second tilting mechanism 9for tilting ladle 6 to discharge its contents at the pouring station asneeded.

Refractory lined covers 10, 11 and 12 are movably mounted above theladles 4, 5 and 6 respectively to reduce the heat loss due to radiationfrom the ladles. A gas burner 13 is mounted in the center of each cover,and these may be used as needed to maintain the desired metaltemperature. Cover 10'is provided with a cut out 14 through which metalis poured into ladle 4, it is secured to arms 15 which are pivotable at16 on column 17, and it can be moved away from ladle 4 by means ofhydraulic cylinder 18 acting through lever arm 19. In a similar fashioncover 11 is secured to arms 20 which are pivotally mounted at 21 oncolumn 22, and it may be moved away from ladle 5 by means of hydrauliccylinder 23 connected to lever arm 24. Likewise, cover 12 is mounted onarms 25 which are pivotally mounted at 26 on column 27 and is movable bymeans of hydraulic cylinder 28 acting through lever arm 29.

In the embodiment of the invention described herein, the turntablecomprises three identical 120 sections 31, 32 and 33 with identicaltilting ladles. When these three sections are secured together they formturntable 1 with three evenly spaced ladles 4, 5 and 6 mounted thereon.Each section moves on flanged wheels which ride on tracks 34. Theturntable 1 is rotated by means of ring gear 36 attached to itsunderside, and the driving means consists of a motor 37 acting throughgear reducer 38. Each of the ladles 4, 5 and 6 are pivotable ontrunnions 39 and a handle 40 is provided on the opposite side of 3 eachladle whereby it may be rotated about trunnions 39 by means of eithertilting mechanism 8 or 9 when the ladle is positioned at either thetreating station or the pouring station.

In FIGURES 2 and 3 the turntable section which is used to make up theturntable 1 is shown in detail. It comprises a car mounted on wheels 51the axles of which are parallel to radii of the turntable circle so thatthey will follow the curved supporting track 34. Projecting verticallyfrom the car are two posts 52 which are supported .by braces 53. Mountedbetween posts 52 is a cradle 54 comprising a bed 55 having two verticalposts 56 reinforced by braces 57, two side plates 58 and a front plate59. This cradle is pivotally mounted between posts 52 by means oftrunnion axles 60 extending through suports 61 on the car posts 52 andsupports 62 on the cradle posts 56. At each of the front corners tongues63 are connected to the underside of the cradle 54 by means of pins 64extending through brackets 65. The tongues 63 angle towards the rearcenter of the cradle and project beyond the rear of the cradle wherethey are tied together by means of handle 66. A ladle 67 (correspondingto ladles 4, and6 in FIGURE 1) is seated in cradle 54 with a pair oftrunnions 68 which project from opposite sides of the ladle positionedin appropriate cut outs in side plates 58 (see FIGURES 4 and 5). Thecontents of the ladle 67 may be dumped through ladle spout 69 byapplying a vertical force on handle 40 thus causing the cradle 54 withladle 67 to pivot about axles 60.

In FIGURE 4, ladle 4 on car 31 is in position to receive metal fromducks nest 7. The ducks nest comprises a base support upon which thenest 71 is supported by a collar 72. The nest comprises a base 73 withspaced apart sides 74 between which is supported the metal holdingvessel 75. The metal holding vessel or duck comprises a main holding pot76 and a long spout 77, and it is pivotally mounted in nest 71 by meansof pins 78 extending through a pair of cars 79 and adjacent nest sides74. The spout 77 may be raised to shut off the flow of metal to ladle 4or lowered to permit metal to flow into ladle 4 through cut out 14 incover 10. This raising and lowering is accomplished by hydrauliccylinder 80 causing the container 75 to pivot about pins 78. While anempty ladle is being moved into position, the hydraulic cylinder isextended to raise the spout 77 thus cutting off the flow of metal to theladle and causing the accumulation of metal in holding pot 76.

Ladle 5 is mounted on car 32 and is positioned at the treating stationwhere the metal can be given any desired treatment such asdesulphurization. Cover 11 which is mounted on arm 20 is shown in itsswing away position where it does not interfere with the introduction oftreating and slagging equipment into the ladle. The cover is moved tothis position by means of hydraulic cylinder 23 rotating shaft 21 towhich arm 20 is secured. Ladle 5 may be tilted by hydraulic cylinder 81to which is attached a hook 82 adapted to engage handle 66. Cylinder 81is pivotally mounted between two posts 83 by means of pin 84, and theposts are strengthened by braces 85. A kick out roller 86 rides againstcam surface 87 and cam roller 88 on hook 82 to assure that the hookproperly engages handle 66.

In FIGURE 5, ladle 6 is shown mounted on car 33 in position at thepouring station. This ladle is dumped by means of hook 90 which engageshandle 66 as it is pulled upward by Wire rope 91, the hook carries camrollers 92 which ride against roadway 93 built on a vertical tower 94.Inside the tower a hydraulic cylinder 95 is mounted by means of pin 96in a vertical direction with the cylinder rod extended from the top ofthe cylinder. The wire rope 91 is threaded around pulley 97 mounted onthe tower and pulley 98 mounted on the end of the cylinder rod 99 andthen secured to the tower. When rod 99 is drawn into cylinder 95 hook 90engages handle 66 and ladle 6 and cradle 54 are pivoted about trunnionpin 60.

In FIGURE 5, ladle cover 12 is not shown since it is essential that itbe moved away from the ladle in order that the ladle may be rotatedabout its pivot point. If it is desirable to keep the cover 12 on theladle 6 during the pouring operation, the cover may be mounted above theladle as shown in FIGURE 6. The cover 13 is attached to a cross beam 100which has arms 101 at its ends. These arms are provided with trunnions102 which are seated in U-brackets on posts 104 in axial alignment withtrunnion pins 60 about which ladle 6 pivots. The back of the cover issupported by a stop, not shown, mounted on tower 94 thus permitting theladies to move transversely under the cover.

The size of the ladles 4, 5 and 6 will depend upon the melting rate andthe amount of time required to analyze and treat the metal at thetreating station. For example, if fifteen minutes is required to analyzethe metal and to treat the metal with the proper agents to obtain thedesired composition while the cupola is melting fortyeight tons perhour, the ladles would be designed to hold twelve or more tons of metal.The ladles should be well insulated to reduce the heat loss and toprevent excessive reduction in metal temperature between the cupolaspout and the pouring station. In addition, the provision of the ladlecovers greatly reduces the radiation losses from the top of the ladles.The covers are spaced three or four inches from the top of the ladles topermit free relative movement between the ladles and covers in thehorizontal direction and to permit the use of the gas burners mounted inthe covers. The gas burners together with proper insulation of theladles permit the metal temperature to be held at the desired level forprolonged periods of time.

This new apparatus is particularly useful in the manufacture of ductileiron pipe. Metal from either a hot or cold blast cupola is received atthe melting station. In view of the ability of the apparatus to conserveheat and maintain the desired temperature, the cupola spout temperaturecan be appreciably lower than is generally the case. As a result evenwith a cold blast acid lined cupola, high melting rates can bemaintained using high steel charges, and the metal temperature obtainedat the cupola spout will be adequate.

When a full ladle is obtained at the melting station the turntable isrotated to transfer the ladle to the treating station where samples aretaken and the carbon and silicon contents of the metal are quicklydetermined. Immediately upon the taking of samples, desulfurization ofthe metal is commenced. This is preferably accomplished by dumpingcalcium carbide onto the surface of the metal and then violentlyagitating the bath for a few minutes with compressed air or nitrogenblown through a submerged tube. As soon as the carbon and silicon valuesare known, the proper amounts of each are injected into the metal. Themetal is then transferred to the pouring station by rotating theturntable 120, where it is poured into transfer ladles for transfer tothe casting machine. The metal may be treated with magnesium andferrosilicon inoculant by placing these in the bottom of the transferladle and covering them with a thin layer of scrap metal. However, othermethods may be used in which case the metal would be poured into theappropriate treating vessel at the pouring station.

From the foregoing, it is apparent the present invention provides anapparatus which permits batch treatment of metal received from a meltingfurnace in such a fast efiicient manner as to be comparable tocontinuous treatment methods in results obtained. While there has beenillustrated and described the presently preferred embodiment of theinvention, this has been set forth as an illustration of the inventionand not as a limitation of the invention. It will be apparent to thoseskilled in the art that changes may be made in the form of the apparatuswithout departing from the scope and spirit of the invention as setforth in the appended claims.

I claim:

1. Apparatus for handling hot metal comprising metal melting facilities,a turntable positioned adjacent the melting facilities, a receivingstation, a treating station and a pouring station evenly spaced aroundthe periphery of the turntable, three open top ladles tiltably mountedon the turntable and evenly spaced thereon so that when any ladle ispositioned at any of said stations the other two ladles will bepositioned at the other two said stations, drive means for rotating theturntable to successively position each of said ladles at each of saidstations, means provided at the receiving station to control the flow ofmetal from the melting facilities to a ladle positioned at the receivingstation, means provided at the pouring station for tilting a ladlepositioned thereat to discharge its contents, and a ladle cover providedat each of said stations to reduce heat loss from the open tops of thethree ladles while positioned at the stations.

2. Apparatus according to claim 1 wherein at least one of the saidcovers has a gas burner mounted therein so as to direct its flamedownward into the ladle positioned thereunder.

3. Apparatus according to claim 1 wherein the melting facilitiescomprise at least one cupola.

References Cited UNITED STATES PATENTS 1,749,083 3/1930 Morris et a1.22-82 2,743,491 5/ 1956 Berry 2279 X 2,842,354 7/1958 Hohne 26638 X3,211,443 10/1965 Starner et a1 266-39 FOREIGN PATENTS 704,620 1954Great Britain.

I. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner.

1. APPARATUS FOR HANDLING HOT METAL COMPRISING METAL MELTING FACILITIES,A TURNTABLE POSITIONED ADJACENT THE MELTING FACILITIES, A RECEIVINGSTATION, A TREATING STATION AND A POURING STATION EVENLY SPACED AROUNDTHE PERIPHERY OF THE TURNTABLE, THREE OPEN TOP LADLES TILTABLY MOUNTEDON THE TURNTABLE AND EVENLY SPACED THEREON SO THAT WHEN ANY LADLE ISPOSITINED AT ANY OF SAID STATIONS THE OTHER TWO LADLES WILL BEPOSITIONED AT THE OTHER TWO SAID STATIONS, DRIVE MEANS FOR ROTATING THETURNTABLE TO SUCCESSIVELY POSITION EACH OF SAID LADLES AT EACH OF SAIDSTATIONS, MEANS PROVIDED AT THE RECEIVING STATION TO CONTROL THE FLOW OFMETAL FROM THE MELTING FACILITIES TO A LADLE POSITIONED AT THE RECEIVINGSTATION, MEANS PROVIDED AT THE POURING STATION FOR TILTING A LADLEPOSITIONED THEREAT TO DISCHARGE ITS CONTENTS,